The present invention relates to the technical field of a digital image processing apparatus for use with digital photoprinters and like machines that read the image on a film photoelectrically and output a print (photograph) having the image reproduced thereon, and more specifically, to an image processing apparatus capable of correcting the red-eye effect of a person and an animal photographed using an electronic flash while securing good productivity.
Most of the images recorded on photographic films such as negatives and reversals (which are hereinafter referred to as “films”) are conventionally printed onto light-sensitive materials (photographic papers) by a technique generally called “direct exposure” (analog exposure) in which the image on a film is projected onto the light-sensitive material for areal exposure.
A printer that adopts digital exposure has recently been commercialized. In this “digital photoprinter”, the image recorded on a film is read photoelectrically and converted into digital signals, which are subjected to various kinds of image processing to produce recording image data; a light-sensitive material is exposed by scanning with recording light modulated in accordance with the according image data, thereby recording a (latent) image which is then processed photoelectrically to produce a (finished) print.
In digital photoprinters, the image is converted to digital image data and exposing conditions can be determined by processing that image data. Hence, by using such digital photoprinters, the correction of washed-out highlights or dull shadows of the due to photography with a back light or an electronic flash, sharpening (sharpness processing), the correction of color or density failures, the correction of under- or over-exposure, the correction of the insufficiency of marginal lumination and various other kinds of image processing can be performed effectively enough to produce prints of high quality that have heretofore been impossible to obtain by the direct exposure technique. In addition, a plurality of images can be composited into a single image or one image can be split into segments or even characters can be composited by the processing of image data. If desired, prints can be outputted after desired editing/processing in accordance with a specific application.
The capability of digital photoprinters is by no means limited to outputting the image as a print (photograph) and they enable the image data to be supplied to computers or stored in recording media such as floppy disks; thus, with digital photoprinters, the image data can be used in various applications other than photography.
Having these features, the digital photoprinter is composed of the following three basic parts; a scanner (image reading apparatus) that reads the image on a film photoelectrically; an image processing apparatus that performs image processing of the read image to determine the exposing conditions for image recording; and a printer (image recording apparatus) that scan exposes a light-sensitive material in accordance with the determined exposing conditions and performs development and other necessary processes to produce a print.
In the scanner, the reading light issuing from an illuminant is allowed to be incident on the film, thereby producing projected light that carries the image recorded on the film; the projected light is then passed through an imaging lens to be focused on an image sensor such as a CCD sensor which performs photoelectric conversion to read the image, which is optionally subjected to various kinds of image processing before it is sent to the image processing apparatus as the image data (image data signals) from the film.
In the image processing apparatus, the image processing conditions are set on the basis of the image data that has been read with the scanner and image processing is applied to the image data in accordance with the thus set conditions, thereby producing output image data for image recording (i.e., exposing conditions) that are subsequently sent to the printer.
In the printer, if it is an apparatus that adopts exposure by scanning with optical beams, the beams are modulated in accordance with the image data supplied from the image processing apparatus and as said optical beams are deflected in a main scanning direction, the light-sensitive material is transported in an auxiliary scanning direction perpendicular to the main scanning direction, whereby the light-sensitive material is exposed to the image-carrying optical beams to form a latent image; the exposed light-sensitive material is then developed and otherwise processed in accordance with its type so as to produce a finished print (photograph) reproducing the image that has been recorded on the film.
Incidentally, the most important factor which affects the image quality of a print such as a portrait containing a person in an image is how the person is finished, and, in particular, a red-eye effect by which the eyes of the person is made red by the effect of the light emitted from an electronic flash in photographing is a serious problem.
As mentioned above, the image processing apparatus in the digital photoprinter obtains output image data by subjecting image data read by a scanner to image processing.
Therefore, it is possible to output an appropriate image by correcting red eyes by image data processing. There has been known a method of correcting red eyes by extracting the image data of an eye region from an image using a commercially available image processing tool such as Photo Retouch Software or the like and subjecting the eye (image data of the eye) to color transformation.
However, when the red eye correction processing performed by the conventional method is applied to an apparatus such as the digital photoprinter and the like to which high productivity is required, there is a problem that a certain degree of technology is required to the operator, processing takes a long time and productivity is lowered although an image of high quality can be obtained by correcting red eyes.